Field emission devices using modified carbon nanotubes

Abstract

The present invention relates to a field emission device comprising an anode and a cathode, wherein said cathode includes carbon nanotubes nanotubes which have been subjected to energy, plasma, chemical, or mechanical treatment. The present invention also relates to a field emission cathode comprising carbon nanotubes which have been subject to such treatment. A method for treating the carbon nanotubes and for creating a field emission cathode is also disclosed. A field emission display device containing carbon nanotube which have been subject to such treatment is further disclosed.

Description

[0001] This application claims the benefit of U.S. Provisional Application No. 60 / 298,193, filed Jun. 14, 2001, hereby incorporated by reference.[0002] The present invention relates to field emission cathodes which use carbon nanotubes.[0003] Field emission devices are devices that capitalize on the movement of electrons. A typical field emission device includes at least a cathode, emitter tips, and an anode spaced from the cathode. A voltage is applied between the cathode and the anode causing electrons to be emitted from the emitter tips. The electrons travel in the direction from the cathode to the anode.[0004] These devices can be used in a variety of applications including, but not limited to, microwave vacuum tube devices, power amplifiers, ion guns, high energy accelerators, free electron lasers, and electron microscopes, and in particular, flat panel displays. Flat panel displays can be used as replacements for conventional cathode ray tubes. Thus, they have application in t...

AI Technical Summary

Benefits of technology

[0008] It is an object of the present invention to provide improved field emission cathodes comprising carbon nanotubes as the emitters, which operate at reduced working voltage, have increased emissions and more emission sites.

[0011] It is still a further object of this invention to provide improved field emission display devices having improved properties such as reduced working voltage, increased emissions and more emission sites.

[0058] Single wall nanotubes are useful in a variety of applications. The tubular structure imparts superior strength, low weight, stability, flexibility, thermal conductivity, large surface area and a host of electronic properties. They can be used as reinforcements in fiber reinforced composite structures or hybrid composite structures, i.e., composites containing reinforcements such as continuous fibers in addition to single wall nanotubes.

Problems solved by technology

The problem with metal emitter tips is that the control voltage required for emission is relatively high, e.g., around 100 V. Moreover, these emitter tips lack uniformity resulting in non-uniform current density between pixels.

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